<h1><code ng:non-bindable=""></code>
    <span class="hint"></span>
</h1>
<div>
    <a href="http://github.com/angular/angular.js/edit/master/docs/content/guide/dev_guide.services.understanding_services.ngdoc"
       class="improve-docs btn btn-primary">Improve this doc</a>

    <div class="developer-guide-page developer-guide-angular-services-understanding-angular-services-page"><p>Angular
        services are singletons that carry out specific tasks common to web apps, such as the
        <a href="api/ng.$http"><code>$http service</code></a> that provides low level access to the browser's
        <code>XMLHttpRequest</code> object.</p>

        <p>To use an Angular service, you identify it as a dependency for the dependent (a controller, or
            another service) that depends on the service. Angular's dependency injection subsystem takes care
            of the rest. The Angular injector subsystem is in charge of service instantiation, resolution of
            dependencies, and provision of dependencies to factory functions as requested.</p>

        <p>Angular injects dependencies using "constructor" injection (the service is passed in via a factory
            function). Because JavaScript is a dynamically typed language, Angular's dependency injection
            subsystem cannot use static types to identify service dependencies. For this reason a dependent
            must explicitly define its dependencies by using the <code>$inject</code> property. For example:</p>

<pre><code> myController.$inject = ['$location'];
</code></pre>

        <p>The Angular web framework provides a set of services for common operations. Like other core Angular
            variables and identifiers, the built-in services always start with <code>$</code> (such as
            <code>$http</code> mentioned
            above). You can also create your own custom services.</p>

        <h2 id="relatedtopics">Related Topics</h3>

            <ul>
                <li><a href="guide/di">About Angular Dependency Injection</a></li>
                <li><a href="guide/dev_guide.services.creating_services">Creating Angular Services</a></li>
                <li><a href="guide/dev_guide.services.managing_dependencies">Managing Service Dependencies</a></li>
                <li><a href="guide/dev_guide.services.testing_services">Testing Angular Services</a></li>
            </ul>

            <h2 id="relatedapi">Related API</h3>

                <ul>
                    <li><a href="api/ng">Angular Service API</a></li>
                    <li><a href="api/angular.injector"><code>Injector API</code></a></li>
                </ul>
    </div>
</div>
